GLP1R and Parkinson disease: However, robust preclinical evidence and promising findings in select subpopulations warrant further RCTs to evaluate their neuroprotective potential, prioritizing long-acting and brain-penetrant agents that effectively engage central GLP-1 circuits for PD treatment.<h4>Registration</h4>The pre-specified protocol of the present systematic review and meta-analysis has been registered in the International Prospective Register of Ongoing Systematic Reviews PROSPERO (registration ID: CRD420251008703).